The present invention generally relates to the treatment of porous materials in order to render them water repellent. More particularly, the present invention relates to silicone compositions suitable for rendering masonry such as brick, concrete, stone, mortar, tile, cinder block, stucco and the like water repellent and stain resistant.
Silicones have been used to render masonry water repellent for many years. The heretofore employed silicones have met with considerable commercial success and are used on all types of masonry. However, the heretofore employed silicones tended to leave the surface of the masonry somewhat tacky and hence caused dirt to adhere thereto. Additionally, many of the previously employed silicones did not maintain excellent water repellency after prolonged exposure to weather nor did they impart stain resistance to the masonry.
U.S. Pat. No. 2,412,470 discloses a process for treating a solid body to render it water repellent which comprises contacting said body with a composition containing, as the active ingredient thereof, a mixture consisting essentially of from about 2.8 to 99.2 weight percent trimethyl silicon chloride and from about 97.2 to 0.8 weight percent silicon tetrachloride.
U.S. Pat. No. 2,574,168 provides a process for rendering porous masonry structures water repellent by applying to such masonry structures a dilute liquid comprising an organic solvent solution of a silicone resin in its B-staged partially condensed form, wherein the concentration of the silicone resin is from about 0.1 to 5 parts by weight, said silicone resin when completely condensed being a heterocyclic and crosslinked condensation product having the formula (R.sub.m SiO.sub.n).sub.x, where x is an integer greater than one, R represents monovalent alkyl or aryl radicals, m is a number less than two but not less than 0.5, and n is a number more than one and not less than about 1.75, the silicon atoms in the resin being linked to the oxygen atoms and the alkyl and aryl radicals being attached to silicon atoms.
U.S. Pat. No. 2,672,455 provides a water repellent for leather which comprises (1) 15 to 50 percent by weight of a titanium compound selected from the group consisting of titanium compounds having the general formula Ti(OR).sub.4 and aliphatic hydrocarbon soluble partial hydrolyzates thereof in which R is an aliphatic hydrocarbon radical or hydroxylated aliphatic hydrocarbon radical, (2) 15 to 70 percent by weight of a methylpolysiloxane copolymer composed of trimethylsiloxane units and SiO.sub.2 units, said units being in such proportion that the ratio of methyl radicals to silicon atoms is from 1.0 to 2.5:1, and (3) 15 to 80 percent by weight of polysiloxane having the general formula R'.sub.n SiO.sub.(4-n)/2, where R' is a C.sub.1-4 alkyl or alkylene radical or a monocyclic aryl radical, and n having an average value of 2 to 2.9, each silicon atom in polysiloxane (3) having at least one R' radical attached thereto.
U.S. Pat. No. 2,678,893 teaches a method for rendering leather water repellent comprising contacting the leather with a solution of a methylpolysiloxane composed of trimethylsiloxane units and SiO.sub.2 units in such proportion that the ratio of methyl radicals to silicon atoms is from 1 to 2.5, said solution containing from 1 to 50 percent by weight of the methylpolysiloxane.
U.S. Pat. No. 2,735,791 relates to a waterproofing composition suitable for application to fibrous organic materials which comprises an aqueous emulsion containing 20 to 60 weight percent, as solids, of a methyl polysiloxanic resin having a CH.sub.3 to Si ratio between 1.3:1 and 1.7:1; 20 to 50 weight percent of a methyl polysiloxanic oil having a CH.sub.3 to Si ratio between 1.9:1 and 2.1:1; and from 8 to 40 weight percent triethanolamine titanate.
U.S. Pat. No. 2,928,798 discloses compositions useful for rendering porous materials water repellent which comprise, by weight, (1) from 10 to 60 percent of a titanium compound selected from the group consisting of (a) orthotitanates having the general formula Ti(OR).sub.4, where R is an aliphatic hydrocarbon radical or an aminated or hydroxylated aliphatic hydrocarbon radical, and (b) aliphatic hydrocarbon soluble partial hydrolyzates of (a); (2) from 25 to 75 percent of a methylsiloxane copolymer containing trimethylsiloxy units and SiO.sub.2 units, wherein the ratio of methyl groups to silicon atoms ranges from about 1 to 1.25, and (3) from 10 to 50 percent of a fluid organopolysiloxane having the formula R'.sub.n SiO.sub.(4-n)/2, where R' represents both lower alkyl radicals and chlorinated phenyl radicals containing an average of 3 to 5 chlorine atoms per phenyl nucleus, the chlorinated phenyl radicals consituting from 5 to 25 percent of the total number of R' radicals, n has an average value between 1.96 and 2.5, and the viscosity is from 10 centistokes to 100,000 centistokes at 25.degree.C.